1. Field of the Invention
The present invention relates to a comminuting tool for a comminuting device having a rotor-stator system or rotor-rotor system and to a method for determining the state of wear of a comminuting tool.
2. Description of the Background Art
The conversion of materials into an intermediate or end product, for example, and therefore also the comminution of materials fall within the field of mechanical process engineering. The category of comminuting machines suitable for this purpose also includes devices with a rotor-stator system or rotor-rotor system. Their rotors are edged with comminuting tools, which over the course of rotation are moved past the tools of a stator or second rotor and comminute the feedstock during interaction with these. Shearing tools, blades, hammers, and the like, for example, are known as comminuting tools.
During the operation of such devices, the comminuting tools are exposed to great mechanical stress, which depending on the type of feedstock results in more or less great wear. With increasing wear, the geometry of the comminuting tools and thereby the effectiveness of the comminution also change. Because of the associated deviations from the optimal starting conditions, the quality of the end product suffers, which deviates in its shape, size, and surface quality from target specifications or is subjected to variations outside the tolerance range. In addition, the energy consumption and heat production within the device also increase with increasing wear of the comminuting tools.
To avoid these disadvantages, it is therefore necessary to check the degree of wear of the comminuting tools at predefined time intervals. The precise determination of the current state of wear of comminuting tools is therefore very important.
In practice, this occurs rather often only by a visual examination without the use of other auxiliary means. The accuracy of the information obtained thereby as expected leaves much to be desired. It is typical in addition to determine the distance of the rotor tool to the stator, thus, the width of the working gap, with use of a pocket rule. This distance increases with increasing wear, and is therefore an indicator of the state of wear of the comminuting tools. This type of wear determination entails the risk, however, that with wear of the stator the reference surface there changes, which results in an incorrect measurement result.